20
12
+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
|               |   |   |       |   |               |       |                   |
+   +---+---+---+   +   +   +---+   +   +---+---+   +---+   +   +---+---+---+---+
|                   |   |   |   |       |           |   |       |               |
+   +---+---+---+---+   +   +   +   +---+---+---+   +   +   +---+   +   +---+   +
|                       |           |           |                   |   |       |
+   +---+   +   +---+---+   +---+---+   +   +---+   +   +---+---+---+---+---+   +
|       |   |                   |       |   |       |                       |   |
+   +   +---+---+---+---+---+---+---+   +---+---+---+---+---+---+---+---+---+   +
|   |               |   |           |   |                   |   |           |   |
+   +   +   +   +   +   +---+   +---+   +   +---+   +---+---+   +   +   +---+   +
|   |   |   |   |   |       |   |       |   |   |                   |       |   |
+---+   +   +   +   +---+   +   +   +---+   +   +---+---+---+---+---+   +   +   +
|   |   |   |   |                                           |           |   |   |
+   +---+   +   +   +---+   +   +   +   +   +---+---+   +---+   +---+---+   +---+
|   |       |   |   |       |   |   |   |           |       |           |   |   |
+   +---+---+   +---+---+   +---+---+   +---+   +   +   +   +---+   +---+---+   +
|                       |       |   |       |   |   |   |   |   |       |       |
+---+   +   +---+---+   +   +   +   +   +---+---+   +---+   +   +---+---+---+   +
|       |       |   |   |   |   |               |   |                       |   |
+   +   +---+   +   +   +   +---+---+   +---+   +   +   +---+---+---+---+---+   +
|   |   |       |   |   |   |       |       |   |   |       |               |   |
+---+---+---+   +   +   +---+   +---+   +---+---+   +---+---+   +---+---+   +   +
|               |               |               |               |               |
+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
